An interface can be words, images, light switches, door handles, or complex hardware or software. Regardless of the type of interface, the same core principles that lead to a usable experience apply:

An early focus on users and tasks

Iterative design

Empirical measurement

Here are five interfaces that these principles apply to and can benefit from usability testing.

1. Surveys

While a survey is itself a means for collecting data, it’s also an interface—usually a combination of words and images delivered via software.

For years we have found one of the best ways to pre-test a survey, and assess the clarity of questions and response options is to usability test it. We have a handful of participants think aloud while filling out the survey. This approach also helps identify what questions might cause confusion and even fatigue points.

2. Presentations

A number of excellent resources can improve the effectiveness of a presentation in both style and substance.

One way to ensure your message is coming through in words and pictures is to assess it with a handful of targeted participants. I learn something new every time I present (what makes sense and what doesn’t) and getting that feedback improves the experience for future talks.

3. Graphs & Visualizations

A good visualization can help an audience or reader better understand data. A bad visualization distorts the message and leads to erroneous conclusions. You can improve a graph or visualization by identifying what the main takeaways are and assessing whether your audience is reaching those same conclusions.

You can even assess multiple visualization alternatives using a remote unmoderated survey with a lot of participants. You can test whether subtle differences in graphical elements (chart junk and different y-scales) help or hurt comprehension. You can also get more sophisticated and measure the time to reach a correct conclusion and the perceived difficulty of interpreting the visualization.

4. Icons

Icons have a rich history in user interface design and are a natural design element to assess and improve iteratively.

While some icons have become legendary, for many applications the right image to represent abstract functionality can be challenging. Instead of relying on conjecture of what makes a good icon, test its effectiveness. Use a mix of approaches for matching functionality to icons; assess recognition and recall both in and out of the context in which the icon will be used.

5. Legal Text

Even if you aren’t a lawyer, you can’t avoid legal language. Legalese is everywhere—from credit card applications, rental car damage waivers, ski resorts, software terms of conditions, and even websites. While we can’t force people to read every word of a privacy policy or software agreement, we can make it easier for people to understand what the terms of the interface agreements are.

There is a laudable effort to make inscrutable legalese understandable to the layperson. It comes down to simplifying language and removing jargon, and testing how well this refined language improves comprehension. It might even lead to more users reading and understanding what they’re agreeing to.